The present invention relates generally to flow control devices, and more particularly to an improvement of the flow control devices of the above-identified application and patents, the disclosures of which are herein incorporated by reference. Referring as an example to the flow control device which is the subject of U.S. Pat. No. 4,884,595, the flow control device disclosed therein comprises a valve body wherein the valve mechanism is disposed within the valve body. The valve closure mechanism utilizes collapsible tubing wherein, when the collapsible tubing is pinched shut, pressure surrounding it collapses the collapsible tubing to block fluid flow through the flow control device.
A problem with the above-described flow control device arises after the flow control device has been in use for a period of time. After a period of use, the collapsible tubings through wear or the like lose their ability to effectively collapse and block fluid flow through the flow control device. At that point in time, the collapsible tubings must be replaced. However, the flow control devices of the above application and patents require that the entire device be disassembled to be able to replace the collapsible tubings. This typically requires removing the flow control device from the pipeline to which it is attached.
Another problem with the flow control device described in the above application and patents is that the configuration of the flow control device cannot be easily changed. That is, if the flow control device is configured as a two-way valve, it is difficult to change it to a three-way valve. The converse is also true. As a result, an inventory of flow control devices in each configuration must be maintained.
It is an object of this invention to provide a flow control device which makes use of the collapsible tubing principle of the above application and patents that can be easily changed from one configuration to another.
It is another object of this invention to provide a flow control device where the valve mechanism is provided in cartridges which can be removably inserted in inlet and outlet ports of the flow control device and wherein the cartridges have collapsible tubings and use the principles described in the above application and patents to block fluid flow through the flow control device.
It is another object of this invention to provide a valve cartridge for a flow control device where the valve cartridge has therein collapsible tubing which acts in accordance with the principles of the above application and patents and wherein the valve cartridge can be replaced when the valve mechanism becomes worn or the like. Further, the valve cartridge is removably inserted into inlet and outlet ports of the flow control device to configure the flow control device.